This invention relates generally to a manufacturing facility for the production of ophthalmic contact lenses, and, in particular to a production computer system for monitoring the production line processes used in the manufacture of contact lenses in a contact lens fabrication facility, with the goal of collecting data to enable investigation into and optimization of the manufacturing process.
The direct molding of hydrogel contact lenses is disclosed in U.S. Pat. No. 4,495,313 to Larsen, U.S. Pat. No. 4,680,336 to Larsen et al., U.S. Pat. No. 4,565,348 to Larsen, and U.S. Pat. No. 4,640,489 to Larsen et al., the entire disclosures of which are hereby incorporated by reference in this patent application. Essentially, these references disclose an automated contact lens production process wherein each lens is formed by sandwiching a monomer between back curve (upper) and front curve (lower) mold sections. The monomer is polymerized, thus forming a lens, which is then removed from the mold sections and further treated and packaged for consumer use.
The manufacturing of contact lenses requires tightly controlled conditions and processes, many of which are monitored by computers and other control devices. Much information, in the form of process conditions and control data, for e.g., that occur during contact lens manufacturing, may be gathered for quality control purposes. However, this entails the acquisition of a tremendous amount of data for each contact lens that is produced, and, additionally, requires a means for processing the data acquired in a way that is suitable for use by operators, engineers, and supervisors, etc., so that they may properly perform their functions. Additionally, some of the information generated may be by human observation, for instance, lens inspection, which is not as reliable as automatic sensors.
There is therefore the need to provide a quality control system that can automatically acquire process control data from a plurality of manufacturing process controllers that control various aspects of contact lens production at process stations in a contact lens manufacturing facility, and, that can automatically process the data for real-time display and archiving purposes.
It would additionally be highly desirable to provide a quality control system that can automatically gather process control data for each specific contact lens at each of the plurality of process stations.
Additionally, it would be highly desirable to provide a quality control system that gathers process control data for each specific contact lens, and, includes means for automatically correlating the data acquired with each individual contact lens produced for storage and optimization purposes.
It would furthermore be highly desirable to provide a quality control system in a contact lens manufacturing facility that enables an operator to determine the specific reason as to why a contact lens has been rejected during an automatic inspection process occurring subsequent to the manufacture of the lens.
An object of the instant invention is to provide a production control system for monitoring process parameters in an automated production line for manufacturing contact lenses wherein the station has a plurality of process stations with each process station having one or more process control devices that control production operations at the respective process station and generates production parameter data therefrom. The system comprises a line monitor device for receiving an externally generated production order including a lot number, product type, and quantity and further coordinates manufacturing processes at each of the plurality of process stations, and tracks order production from the beginning to the end of the production line; a plurality of cell monitor devices for retrieving the production data from one or more process control devices and processing the data to ensure that production data are within predefined setpoints; and, further includes an interface device for enabling operator activation and completion of orders at each process station and for accessing line status information from the line monitor device and production data from said cell monitor device for real-time viewing of respective line status and device status information.
Another object of the invention is to provide a quality control system that gathers process control data in machine cycle time increments for each specific contact lens that is being produced.
Still another object is to provide a quality control system that includes a data acquisition system having a means for obtaining selected data samples from different device processes and manual audits for statistical purposes.
Yet still another object is to provide a quality control system that includes a data acquisition system wherein the means for obtaining data samples from different device processes is user configurable.
Additionally, another object of the invention is to provide a quality control system that gathers process control data for each lens at each manufacturing process station of a contact lens production line, and includes automatic means for automatically storing the data in a relational database for prospective and retrospective analysis.
The above objects are achieved in a quality control system for optimizing process parameters in an automated production line for producing contact lenses. The system comprises a plurality of process control means for controlling one or more process stations of the production line, each of the control means regulating a plurality of process control devices that each control specific production parameters used in the automated manufacture of contact lenses at the process station(s).
Further benefits and advantages of the invention will become apparent from a consideration of the following detailed description given with reference to the accompanying drawings, which specify and show preferred embodiments of the invention.